Tupolev Tu-121
Tupolev, however, was worried about Nikita Khrushchev's growing interest in rocket weapons.The NORAD system, which was being developed and deployed by the United States at the time was practically impermeable for the strategic bombers of that era.Tu-121 was conceived as an aircraft able to reach speeds of over 2,000 km/h and a flight altitude of 50 km which would allow it to easily penetrate both American air- and missile defence systems.However, even at the early stages, Tupolev himself realized that his bureau was unable to develop such an aircraft.The aircraft was a full-metal monoplane made almost entirely of traditional materials.